1. Field of the Invention
The present invention relates to an audio tape cassette audio tape combination which is suitable for recording high quality sound with less noise and a method for producing the audio cassette tape. More particularly, it relates to an audio tape cassette used together with an audio cassette tape which exhibits less deterioration in output-signals and less drop out of signals.
2. Description of the Related Art
Recently, [an] audio cassette tapes have been required to record high quality sound with less noise, as compact discs becomes popular. Therefore, in order to prevent vibration of a cassette shell, a softer material for the cassette shell is required over the conventional materials selected.
In the prior art, there is used a conventional cassette shell which is made of polystyrene resin, but this resin is hard and has less vibration absorbance at room temperature. In order to satisfy the demand mentioned above, it is proposed to use a new cassette shell which is made of polypropylene resin and, further, to add an inorganic powder such as calcium carbonate, talc, zinc oxide and mixtures thereof as a filler so as to increase the density of the resin.
In order to reliably reproduce sound from a source, some recent audio tape cassette tapes have been proposed having a back coating layer which has a proper roughness to give a proper friction condition with the tape transportation parts of a recording-reproducing apparatus so as to improve runability of the tape.
It is popular to form the back coating layer from a paint comprising certain size inorganic particles dispersed in a binder.
However, since the binder is too weak to hold the inorganic particles in the back coating layer formed from a paint, the particles easily drop in the form of pieces, accumulate on a site at which a tape and a guide part are contacted and then form minute protrusions at the site. As a result, the minute protrusions push the running tape from the back coating side to cause defects, such as cracks and streaks, in the magnetic layer.
The defects in the magnetic layer may cause various problems such as drop out.